First, and I'm pretty sure this is the culprit, uninstall Gigabyte EasyTune6. After you are done installing, pull up the search dialog and search for GDRV.sys and ensure that it is also gone, if not, delete it.
Second, AVG can cause system instability. Please remove it and install Microsoft Security Essentials, at least until we are done with testing.
Third, Update your BIOS, you are on revision F1. BIOS updates often address stability issues. If you chose to update your BIOS, you do so at your own risk.
Fourth, if all else fails, Stop 0x124 - what it means and what to try
if you need any help with the steps listed, please let us know. Do one step at a time and take note of system behavior.